Abstract

The study assessed potential to exceed occupational exposure limits while spraying paint with and without a silver nanoparticle biocidal additive. A tradesperson performed the tasks in a sealed chamber with filtered air supply. Integrated air sampling entailed transmission electron microscopy with energy dispersive X-ray analysis, direct-reading of particle number concentrations, and determination of silver mass concentration by NIOSH Method 7300. Silver nanoparticles were primarily embedded in paint spray droplets but also observed as isolated particles. Using an α-level of 0.05, median nanoparticle number concentrations did not differ significantly when spraying conventional vs. biocidal paint, although statistically significant differences were observed at specific particle size ranges <100 nm. The geometric mean concentration of total silver while spraying biocidal paint (n = 6) was 2.1 µg/m³ (95% CI: 1.5–2.8 µg/m³), and no respirable silver was detected (<0.50 µg/m³). The results address a lack of silver nanoparticle exposure data in construction and demonstrate the feasibility of a practical sampling approach. Given similar conditions, the measurements suggest a low probability of exceeding a proposed silver nanoparticle exposure limit of 0.9 µg/m³ as an airborne 8-hr time-weighted average respirable mass concentration. A full workday of exposure to respirable silver at the highest possible level in this study (<0.50 µg/m³) would not exceed the exposure limit, although limitations in comparing short task-based exposures to an 8-hr exposure limit must be noted. There was airflow in the study chamber, whereas exposure levels could increase over time in work environments lacking adequate ventilation. Potential to exceed the exposure limit hinged upon the respirable fraction of the paint mist, which could vary by material and application method. Additional research would improve understanding of silver nanoparticle exposure risks among construction trades, and biological responses to these exposures. Given the potential for exposure variability on construction jobsites, safety and health professionals should be cognizant of methods to assess and control silver nanoparticle exposures.

摘要

该研究评估了使用或不使用银纳米颗粒杀菌添加剂进行喷漆时超出职业接触限值的可能性。一名技工在一个带有过滤空气供应的密封室中执行任务。集成空气采样需要透射电子显微镜与能量色散 X 射线分析、直接读取颗粒数浓度以及通过 NIOSH 方法 7300 测定银质量浓度。银纳米颗粒主要嵌入油漆喷雾液滴中，但也观察为孤立的颗粒。使用 0.05 的 α 水平时，喷涂传统涂料与杀菌涂料时，中值纳米颗粒数浓度没有显着差异，但在 <100 nm 的特定颗粒尺寸范围内观察到统计学显着差异。喷涂杀菌涂料时总银的几何平均浓度 (n = 6) 为 2.1 µg/m ³ (95% CI: 1.5–2.8 µg/m ³ )，未检测到可吸入银 (<0.50 µg/m ³ ) 。结果解决了建筑中银纳米粒子暴露数据的缺乏，并证明了实用采样方法的可行性。在类似条件下，测量结果表明，以空气中 8 小时时间加权平均可呼吸质量浓度计，超过建议的银纳米颗粒暴露限值 0.9 µg/m ³的可能性较低。尽管必须注意将基于任务的短期暴露与 8 小时暴露限制进行比较的局限性，但在本研究中，整个工作日暴露于最高可能水平的可吸入银 (<0.50 µg/m ³ ) 不会超过暴露限制。研究室内有气流，而在缺乏足够通风的工作环境中，暴露水平可能会随着时间的推移而增加。超过暴露限值的可能性取决于漆雾的可呼吸部分，这可能因材料和应用方法而异。额外的研究将提高对建筑行业中银纳米粒子暴露风险以及对这些暴露的生物反应的了解。鉴于建筑工地暴露的潜在变化，安全和健康专业人员应了解评估和控制银纳米颗粒暴露的方法。